Control rods are well known components of heavy truck suspensions wherein they are widely used as torque rods and referred to as "torque rods". The present invention relates to new and improved control rods particularly suited for heavy truck suspensions wherein control rods have been a standard component for over seventy-five years. A control rod is a linkage, which transmits longitudinal and transverse forces from the axle to the frame or suspension component of a vehicle such as a heavy duty truck. The forces acting on the ends of a control rod linkage include torsion, radial, axial and conical patterns as described in SAE J 1183, Elastomeric Bushing TRAC.
The control rods provided by the present invention are characterized by having a spacer rod, which is generally C or U-shaped in cross-section, to the opposite ends of which bushing tubes are welded. The opposite ends of the spacer rod are shaped or contoured so as to have mating or line engagement with the exterior side surface of the bushing tube which is welded to each end of the spacer rod. The welds joining each end of the spacer rod to the bushing tubes are at least substantially complete in that they follow the interior and exterior of each end of the spacer rod. By reason of their C or U-shaped open cross-section the spacer rods have excellent strength on the basis of their weight and permit at least the substantially complete perimeter welds that join their opposite ends to the bushing tubes and thereby provide maximum strength.
Accordingly, the object of the invention generally stated is the provision of new and improved control rods for truck suspensions and other uses, which are economical to make in a variety of sizes utilizing readily available production procedures and equipment. Specifically, the invention applies to low volumes of multiple length low volume control rods.
For a more complete understanding of the nature and scope of the invention reference may now be had to the following detailed description of one embodiment taken in conjunction with the accompanying drawings wherein: